反应详情

To 2-trifluoromethylphenyl-lithium prepared from 18.9 g. of n-butyl-lithium and 65.2 g. of 2-bromobenzotrifluoride in 480 ml. of dry ether, a solution of 8.3 g. of 2',4'-dihydroxy-propiophenone in 85 ml. of dry ether is added dropwise, with stirring at a temperature between 0° C. and -5° C. The reaction mixture is stirred at room temperature for further two hours. After cooling the mixture is poured onto a 10% solution of ammonium chloride in ice water. The phases are separated and the aqueous phase is extracted with ether. The organic phase is washed to neutral with water, dried over anhydrous magnesium sulfate, decolored with activated carbon, filtered, and ether is distilled off under reduced pressure. As a residue 15 g. of an oily product are obtained, which is then chromatographed on a silica gel column by elution with dichloromethane. Dichloromethane is then distilled off under reduced pressure, and the solid residue is crystallized from a mixture of n-hexane and ethyl acetate to yield 6.9 g. of the named compound, melting at 143° to 144° C.

1. stirringThe reaction mixture is stirred at room temperature for further two hours
2. temperatureAfter cooling the mixture
3. customThe phases are separated
4. extractionthe aqueous phase is extracted with ether
5. washThe organic phase is washed to neutral with water
6. dry with materialdried over anhydrous magnesium sulfate
7. filtrationfiltered
8. distillationether is distilled off under reduced pressure
9. customof an oily product are obtained
10. customwhich is then chromatographed on a silica gel column by elution with dichloromethane
11. distillationDichloromethane is then distilled off under reduced pressure
12. customthe solid residue is crystallized from a mixture of n-hexane and ethyl acetate
13. customto yield 6.9 g